Earlier quoted context omitted.
And sometimes they loved MSMAIL for the weirdest reasons... MSMAIL was designed for Win3.x. Apps didn't have multiple threads. The MSMAIL client app that everyone used would create the email to be sent and store the email file on the system. An invisible app, the Mail Pump, would check for email to be sent and received during idle time (N.B. Other apps could create/send emails via APIs, so you couldn't have the email…
I re-wrote MSPAGER for Exchange. Hoo boy what a hack that was! A VB3 app running as a service, essentially. I don't know if you remember romeo and juliet; those were PCs pulled from pc-recycle by a co-worker to serve install images.
Also, I survived Bedlam DL3 (but I didn't get the t-shirt).
see https://techcommunity.microsoft.com/blog/exchange/me-too/610... for the explanation for the Bedlam reference.